PCI: Export pci_ats_disabled() as a GPL symbol to modules

Building drivers for ATS-aware IOMMUs as modules requires access to
pci_ats_disabled(). Export it as a GPL symbol to get things working.
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Tested-by: John Garry <john.garry@huawei.com> # smmu v3
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/pci/pci.c

@@ -131,6 +131,7 @@ bool pci_ats_disabled(void)
 {
 	return pcie_ats_disabled;
 }
+EXPORT_SYMBOL_GPL(pci_ats_disabled);
 
 /* Disable bridge_d3 for all PCIe ports */
 static bool pci_bridge_d3_disable;